What is a cataract?
Inside the eye there is a lens which focuses light entering the eye on to
the retina which is the light sensitive surface at the back of the eye. This
is very similar to a camera which has a lens to focus light on to the film.
If the whole or part of the lens within the dog's eye becomes opaque this is
called a cataract.
What causes cataracts?
Some cataracts are the result of injury or diseases such as sugar diabetes.
Some appear to occur spontaneously and are age related. However in the dog by
far the greatest number of cataracts are inherited.
Are some breeds more prone than others?
Many breeds of dogs in the United Kingdom are affected with hereditary cataracts,
among these are the American Cocker, Labrador, the Poodle, the Boston Terrier
and the Welsh Springer Spaniel to mention but a few.
Will my dog go blind?
If cataracts occupy less than 30% of the lens or only one lens is affected
they will often go unnoticed by the dog. When the opacity is affecting about
60% of the total lens area, vision impairment is usually apparent. If the opacity
progresses to 100% of the lens the dog is then unable to see. However whether
the cataract remains static or does progress depends on the type of cataract,
the breed and other factors.
Can anything be done to prevent my dog from going blind?
If the lens is sufficiently opaque to impair vision it can be removed by specialist
surgical techniques. Following this operation of lendectomy the dog has a good
chance of seeing again but the outcome cannot be guaranteed.
How old will my dog be if he does go blind?
Since the major cause of cataract is hereditary, cataract progression varies
from breed to breed. In some breeds cataracts will develop relatively early
in life whereas in others the first signs are detected when the dog is several
years old and progression is so slow that dogs still have reasonable sight when
into old age.
If the condition is hereditary, can nothing be done to prevent it being
This is a situation where prevention is better than cure. The joint British
Veterinary Association/Kennel Club/International Sheepdog Society eye disease
certification scheme offers breeders an excellent chance to make sure they are
producing puppies from disease free stock.
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